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Alpine 3555 amp keeps cutting off

Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=8999
Printed Date: May 22, 2024 at 12:04 AM


Topic: Alpine 3555 amp keeps cutting off

Posted By: jacktoad
Subject: Alpine 3555 amp keeps cutting off
Date Posted: February 03, 2003 at 11:39 AM

i have a couple of questions and appreciate any help on these:
1. i purchased a used Alpine 3555 amplifier and connected it to my car's Blaupunkt head unit and a set of 6x9 Infinity speakers. the amplifier is rated 50w RMS x 4  @ 4ohm.  the amp powers the speakers for 10 - 15 minutes before it starts cutting off. it cuts off and then will cut back on for a second or 2 before cutting off again. the indicator light on the amp goes from green to red as this is going on and off.  it happens regardless of volume level. when i feel the amp, it does not feel hot at all...not even warm really. so it does not seem as though it is overheating. i am sure the wiring is correct, as it is pretty straight forward. the power lead is fused within inches of the battery and the ground wire is solidly connected to the metal car body only inches from the amp. both leads are 8 gauge monster cable.  any ideas as to why the amp starts shutting down??

my Blaupunkt head unit is rated at about 55 watts per channel @ 4 ohm. which leads to my 2nd question...
2. since my head unit is 57.5 watts per channel....do i gain ANYTHING by putting in an amplifier that is anything less then 57.5 watts per channel?



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music is best:-)



Replies:

Posted By: jacktoad
Date Posted: February 03, 2003 at 3:08 PM

oh sh*&%$@!!!!!!  here is an update:

at lunch, when i got in my car, the amp did not power on successfully when i switched on the head unit(the light just stayed red).  and then, the status light went out completely. both 20A inline fuses(integrated into the amplifier) were blown.  i re-sanded the body where the ground connects, just to be sure it was bare,  i then reconnected the ground lead.   before installing 2 new 20A fuses, i removed the power lead 50A inline fuse.  after installing the 2 20A fuses, i reconnected the 50A power lead fuse.   by the time i got back inside my car, the amp was smoking!!!!   WTF??  i disconnected the power lead to the amp to try and prevent any further damage.  and the 2 20A fuses i just installed are still intact.  so....i am guessing that i have screwed this amp completely.  but i would sure like to know where i messed up. 

i have a new RF amp that i am going to take to a professional installer.  but i would like to find out what was wrong with my install of the used amp first.  because, like i said, it worked fine for 10 - 15 minutes after each startup.  so i would hate to have it look like the RF gets installed with no problems only to have it blow the next day.

anybody??  anything???



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music is best:-)




Posted By: pervitizm
Date Posted: February 03, 2003 at 5:35 PM
The same thing happen to me and my boss 4 channel. What had happen was that one of my speaker wires was touching the other (negative touching a postive wire = a bad things). Anyway my amp would cut on and off just like your til finallyl I blew the fuse. So I put a new fuse in and the amp came on and played for about 40 seconds before I notice the smoke. All I can say is that you make sure that all your amp wires are properly secure cause if there not then your gonna smoke your amp.

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live & die 4 tha luv of BASS!!!!




Posted By: jacktoad
Date Posted: February 04, 2003 at 4:11 PM
thanks for the reply..... i pulled all speaker wires off.   in fact, the only connections left are the power lead, the ground wire, and the turn on wire from the head unit.  the unit just keep getting hotter and begins to smoke after 1/2 a minute or so.  be damned if i know what i did wrong. but i did it good:-(

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music is best:-)




Posted By: NyxBass
Date Posted: February 04, 2003 at 11:36 PM

Could be that it is just used, and used hard. caps, MOSFETS's, Diodes, they all can fail after use. Especially if it wasn't alway streated well( not attached properly and bubped around, on a vibrationg box, dropped...) then it could have been internally damaged. Sorry to have it happen ; (   I'm not sure if there's any recourse or anything, maybe you could send it to Alpine, but I'm not sure.



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/NyxBass




Posted By: Velocity Motors
Date Posted: February 05, 2003 at 5:25 AM
You fried some resistors and the MOSFET chip inside the amp. It happens alot on the older Alpine amplifiers after 10 years or so. I had the same amp and it costed about $ 100.00 to replace and fix this problem.

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Jeff
Velocity Custom Home Theater
Mobile Audio/Video Specialist
Morden, Manitoba CANADA





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